Thomas Phinney wrote:
>> It's been mentioned on more than one occasion that OpenType spec has historically been and still is a font format specification, not a text layout implementation spec. This is the reason why some of the information on layout features including their default values, feature interactions and layout engine behavior isn't there. As much as we would want to change this, it's not something that can be easily fixed.
> It is my personal opinion that we can and should move in that
> direction, even if we do it piecemeal.
Adam Twardoch has been working on annotations to the OTL feature
definitions for some time, which even if not formally incorporated into
the spec would be a helpful implementation guide, one that might stand
alone as a separate document if necessary. These annotations include
clearer indication of feature ordering, relationships to script and
language level shaping, and systematic notation of default states of
individual features and user activation options.
If you think this would be helpful, feel free to pester Adam to get it
finished. :)
John Hudson